This invention relates to shoes adapted for both walking and rolling.
There have been several proposals over the last century, and earlier, for walking shoes that can be readily converted to function temporarily as roller skates. A principal advantage to such shoes is the enhanced flexibility in transportation modes that they afford. Most are familiar with the rigid skate frames from several years ago that strapped to the underside of practically any normal walking shoe to permit the wearer to roll upon four wheels arranged two forward, two rear, in a forward or normal walking direction as in a standard roller skate. There is at least one walking shoe on the market that contains wheels that can be retracted into the sole of the shoe for walking, and then extended for rolling. Of course, such shoes require soles with thicknesses sufficient to fully contain such rollers when retracted, but have the advantage of not requiring their rolling parts to be carried separately while walking.
In a rolling mode with these and standard roller skates, the wearer generally is able to propel himself along with alternating forward thrusts with each foot, in a motion similar to ice skating. The direction of travel is generally determined by the fore-aft or toe-heel axis of the foot. In-line skates have their wheels aligned along the fore-aft center line of the shoe, and can provide some directional control by tilting the skate to change the camber of the wheels. Some in-line skates have been employed for sliding down railings in a direction perpendicular to the fore-aft shoe centerline, either by sliding down the railing with the railing positioned between a middle pair of rollers, or on skid plates between the wheels.
There is another shoe that has a removable roller mounted in a cavity the heel of the sole. For walking, the roller can be completely removed from its cavity. In a rolling mode, the wearer can, with practice and balance, roll in a forward direction upon the cylindrical roller with ankle locked and shin flexed. To obtain forward momentum, the wearer is instructed to run on the forward portions of the soles, and then lean back to engage only the heel rollers of both shoes with the ground for sustained rolling in the fore-aft direction as determined by the roller geometry and orientation.
Skateboarding is yet another mode of transportation and sport popular with young people. Skateboards are generally characterized as boards supported by forward and rear xe2x80x9ctrucks,xe2x80x9d each having a pair of wheels mounted upon a tiltable axle. While rolling forward on the board, side-to-side weight fluctuations tilt the board and cause a shift in the rolling direction of the wheels to provide controllable steering of the board. The rolling direction is thus determined by the orientation of the wheel axles, although the normal rolling direction is along a major fore-aft axis of the board. It is common for the skateboarder to place her feet at an angle with respect major board axis, with one foot behind the other, similar to the stance of a surfer on a surfboard.
I have realized that a generally enjoyable and stable transportation mode is effected with a convertible shoe that enables rolling along a direction other than the walking direction determined by the fore-aft shoe centerline, and by new and improved rolling shoe and truck assembly constructions.
According to one aspect of the invention, a shoe defines a normal walking direction and has a sole defining a forward region positioned beneath toes and at least part of a ball of a foot received within the shoe. The sole has a lower surface exposed across the forward region to engage a supporting surface for walking thereon. The shoe also has a roller secured to the sole and disposed rearward of the forward region. The roller is mounted to rotate about an axle defining a primary axis of rotation extending at an angle of between about zero and 45 degrees to the walking direction, as viewed from above the shoe, for rolling sideways along a support surface.
By xe2x80x9cnormal walking directionxe2x80x9d I mean the direction generally defined by a fore-aft or toe-heel axis running along the length of the shoe.
Preferably, the roller is either removable or retractable, and the sole is sufficiently flexible to comfortably bend during walking.
In many instances, the roller forms a lowermost portion of the shoe.
In some embodiments, the axle is mountable to the sole in a plurality of selectable axis orientations. In some cases the axle defines, in one such orientation, an alternate axis of rotation extending substantially perpendicular to the walking direction.
Some shoes include two such rollers, which may be spaced apart laterally across the sole. Preferably, centers of the two rollers have a lateral spacing of about 20 percent of an overall length of the sole. In some instances, the rollers are spaced apart along the walking direction, with midplanes of the two rollers preferably spaced apart along the walking direction by a distance of about 30 percent of an overall length of the sole.
In some embodiments, the shoe also has a grinding surface disposed between the rollers and defining a laterally extending channel for receiving a rail. The grinding surface may be a circumferential surface of a rolling member, or be rigidly secured to the sole of the shoe, for example.
In some instances, the sole defines a cavity having an opening at the lower surface of the sole, with the roller partially disposed within the cavity and extending through the cavity opening.
In some such instances, the roller axle is mounted to a support cup spanning the roller and disposed within the sole cavity. The support cup may be removable from the sole cavity, or the support cup, roller and axle may be removable from the sole cavity as a unit.
In some embodiments, the support cup is selectively positionable in the cavity in a first position for rolling, in which the roller extends through the cavity opening, and a second position for walking, in which the roller is fully recessed within the cavity. Preferably, the cup encloses the roller within the cavity in said second position for walking.
The roller may have one or more of the following features: the roller is elongated, the roller is barrel-shaped, the roller is a wheel, the roller contains a bearing (such as one with rolling elements) supporting the roller on the axle, and/or the roller is cylindrical.
In many embodiments, the roller is disposed in an arch region of the sole.
In some arrangement, the roller defines a rolling surface spanning a distance of at least about 2.0 inches (5 centimeters), preferably at least 2.5 inches (6.3 millimeters), along the sole. The rolling surface preferably spans at least about 15 percent (more preferably, at least about 20 percent, and most preferably at least about 25 percent) of an overall length of the shoe.
In some advantageous constructions, the axle is secured to the sole through a compliant mount that allows tilting of the axle with respect to the sole to vary direction of travel while rolling upon the roller.
In some cases, the axle defines a canted kingpin axis about which the axle rotates to induce yaw with respect to a rolling direction. The axle may be secured to the sole through a compliant mount, for example, that resiliently deforms as the axle is rotated about its kingpin axis.
In some embodiments the axle carries two rollers, one disposed on either side of the kingpin axis. The rollers may be cylindrical, for example, mounted for rotation about the axle through separate bearings containing rolling elements. Preferably, a fore-aft distance between midplanes of the rollers is about 3.0 inches (76 millimeters), or about 30 percent of an overall length of the sole.
The kingpin axis is defined in part, in some embodiments, by a pin of the axle disposed for rotation within a socket of axle mounting structure secured to the sole.
The axle is preferably disposed in an arch region of the sole, between the forward region and an exposed heel region of the sole, and may be selectively removable from the sole for walking.
In one preferred embodiment, the shoe also has a roller mounted to rotate about a fixed axle laterally spaced from the axle with the canted kingpin axis, for additional stability during rolling. Preferably, the fixed axle is disposed on a side of the kingpin axis facing an inner side of the shoe.
In some embodiments, the shoe has at least two rollers, each mounted for rotation about corresponding, independent axles. Each axle defines a canted kingpin axis about which the axle rotates to induce yaw with respect to a rolling direction, with the axles spaced apart laterally across the sole.
In some configurations, each axle carries two rollers, one disposed on either side of its kingpin axis. Preferably, the two rollers together define a wheelbase of about 20 percent of an overall length of the shoe.
In some cases, each kingpin axis extends upward toward an adjacent side of the shoe, for particularly aggressive maneuverability.
Preferably, both axles and their associated rollers are completely disposed within a shoe width defined by the exposed forward region of the sole, so as to not add to the overall width of the shoe.
In some embodiments, the roller defines at least two support surface contact points separated by at least 1.5 inches (38 millimeters). The contact points may be defined on a single rolling member, or on at least two independently rotatable rolling members. In some cases, the rolling member is shaped to engage a flat, horizontal supporting surface at one of the contact points in a first roller tilt direction, and the other of the contact points in a second roller tilt direction. In some other cases, the rolling member is shaped to engage a flat, horizontal supporting surface at both contact points simultaneously.
According to another aspect of the invention, a shoe defines a normal walking direction and has a sole defining a forward region positioned beneath toes and at least part of a ball of a foot received within the shoe. The sole has a lower surface exposed across the forward region to engage a supporting surface for walking thereon. The shoe also has a roller secured to the sole and disposed rearward of the forward region. The roller is mounted to rotate about an axle defining a primary axis of rotation non-perpendicular to the walking direction as viewed from above the shoe.
Various embodiments of this aspect of the invention include features recited above with respect to embodiments of the first-recited aspect.
According to a third aspect of the invention, a shoe defines a normal walking direction and has a sole having a lower surface exposed for engaging a supporting surface for walking thereon. The sole defines a cavity having an opening at the lower surface of the sole, with a roller partially disposed within the cavity and extending through the cavity opening. The roller is mounted to rotate only about a primary axis of rotation for rolling along a support surface in a direction other than the walking direction.
Various embodiments of this aspect of the invention also include features recited above with respect to embodiments of the first-recited aspect.
According to a fourth aspect of the invention, a shoe has a heel portion and a toe portion and defines a normal walking direction, and has a flexible sole with a lower surface exposed for engaging a supporting surface in a walking mode. The sole defines a cavity extending into the sole rearward of the toe portion from an opening at the lower surface and at least partially containing a removable roller extending through the opening for rolling against the supporting surface in a rolling mode. Notably, the roller is mounted to rotate about an axis extending at an angle of between about zero and 45 degrees to the walking direction, as viewed from above the shoe.
Various embodiments of this aspect of the invention also include features recited above with respect to embodiments of the first-recited aspect.
According to a fifth aspect of the invention, a rolling shoe has a sole, a steerable truck assembly with a pair of rollers mounted to rotate about an axle secured to the sole through a compliant mount that allows tilting of the axle with respect to the sole to vary direction of travel while rolling upon the roller, and a non-steerable roller mounted to rotate about a fixed axle laterally spaced from the axle of the steerable truck assembly.
Various embodiments of this aspect of the invention also include features recited above with respect to embodiments of the first-recited aspect.
According to a sixth aspect of the invention, a method of personal locomotion is provided. The method includes donning a pair of shoes each defining a normal walking direction and having a sole defining a forward region positioned beneath toes and at least part of a ball of a foot received within the shoe and having a lower surface exposed across the forward region to engage a supporting surface for walking thereon; and a roller secured to the sole and disposed rearward of the forward region, the roller mounted to rotate about an axle defining a primary axis of rotation extending at an angle of between about zero and 45 degrees to the walking direction, as viewed from above the shoe, for rolling sideways along a support surface. The method also includes accelerating in a desired direction corresponding to the normal walking direction by engaging the forward regions of the soles against a support surface, and then repositioning the shoes to engage the rollers against the support surface, to roll in the desired direction at an angle to the normal walking direction defined by the shoes.
In some cases, the support surface is of a sidewalk.
The step of accelerating may include walking or running upon the forward regions of the shoe soles, for example.
In some cases, the shoes are repositioned to roll in a direction substantially perpendicular to the normal walking direction defined by the shoes.
In some practices of the method, the repositioning of the shoes includes lifting each shoe from the support surface, rotating the shoe away from the direction of acceleration, and then engaging the roller upon the support surface.
Various embodiments of this method also involve shoes with other features recited above with respect to embodiments of the first-recited aspect.
According to yet another aspect of the invention, a steerable truck assembly includes a rigid mounting bracket defining compartments on either side of a canted kingpin, an axle extending generally perpendicular to the kingpin and carrying a pair of rollers, with the axle mounted for angulation about the kingpin for steering, and compliant bushing blocks disposed within the compartments of the bracket and arranged to be resiliently compressed between the bracket and a broad adjacent surface of the axle during angulation from a neutral axle position, to bias the axle toward its neutral position.
In some embodiments, the bushings are wedge-shaped and/or molded of polyurethane.
Advantageously, some embodiments of the truck assembly have an overall height of less than about 1.0 inch (25 millimeters), and are well-suited for direct mounting beneath shoe soles.
In some cases, the compartments are defined on either side of a central bracket web extending from a bracket base to a side of the kingpin.
In some embodiments, the axle has a central body defining an open circular slot for receiving the kingpin, with the slot encompassing, in cross-section, more than 180 degrees of a defined circle, for radially retaining the pin.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.